1. Field of the Invention
The present invention relates to a motor, and more particularly, to a motor allowing for a change in a coupling structure of a base plate and a sleeve holder to thereby enhance the internal rotational force and verticality of the sleeve holder on the base plate.
2. Description of the Related Art
In general, a spindle motor, installed inside an optical disk drive, rotates a disk so that an optical pick-up mechanism can read data recorded on the disk.
According to the related art, a spindle motor has a plurality of notches disposed around a sleeve holder insertion hole formed in a base plate. After a sleeve holder is inserted into the sleeve holder insertion hole, a coupling rack of the sleeve holder is subjected to caulking or spinning to thereby cause the sleeve holder to be fixed to the base plate.
The coupling rack of the sleeve holder is press-fitted to the notches, so an increase in internal rotational force may be realized within the sleeve holder.
When the sleeve holder is fixed to the base plate in the above-described manner, the coupling rack needs to be further press-fitted to wherever the notches are formed. This causes a problem in completing caulking or spinning.
Also, if the degree of press fitting is different in individual notches, the flatness of the base plate may be distorted.
In the case that the flatness of the base plate is distorted, the verticality of the sleeve holder on the base plate is reduced and the internal rotational force of the sleeve holder, induced by high-speed rotations, is also reduced.